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How Smart is a Fish?

Published August 19, 2011 in Dr Peto Says, What's New |
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Dogs are responsive. You talk, tails go into a wagging frenzy! Fish, not so easy. It is not like we get the frequent opportunity to really interact with them – and for anyone who has seen a goldfish repetitively doing the rounds in its bowl, it is easy to buy into the old adage that fish have only a three-second memory.

Research may suggest the possibility that a fish circles its bowl because it really is just impossibly bored, not because it does not remember that it just did it again and again and again. What does Dr. Kevin Warburton, adjunct researcher with Charles Sturt University’s Institute for Land, Water and Society, have to say about the three-second memory of a fish? “Rubbish!”

Warburton, who has been studying fish behaviour for years says, “There’s been a lot of work done over the last 15 years on learning and memory in fish and it has been found that fish are quite sophisticated. Fish can remember prey types for months; they can learn to avoid predators after being attacked once and they retain this memory for several months; and carp that have been caught by fishers avoid hooks for at least a year. That fish have only a three second memory is just rubbish.”

Some of Dr Warburton’s experiments have been on how fish learn to handle different types of prey. “What came out, unexpectedly, was that while they were learning about their prey, their foraging efficiency went down,” he said. “With one type of prey, the fish got more and more efficient at catching their food, but when we put two different types of prey in together, their overall efficiency dropped. We think it was because of they suffered from divided attention. It’s a cost of learning.” Did you hear that? Learning.

Another example of fish memory was that some fish avoid predators after being attacked once, a memory which can be retained for several months, not just three seconds. Warburton said fish also exhibit behaviours that we tend to think as human.

“Some behavioral traits that we think are very human, such as deception, fish have as well,” said Warburton. “Fish can recognize other individuals and modify their own behaviour after observing interactions between other individuals. For example Siamese fighting fish will attack other members of the same species more aggressively if they have seen them lose contests with other fighters.”

Dr Warburton said that fish also check out suspected predators to gauge the level of potential threat. “For added safety, they often do this as cooperating pairs, with the two fish taking the lead alternately,” he said. “They will approach predators most closely when they have cooperated in previous inspections.”

In reef environments, “cleaner” fish remove and eat parasites from larger “client” fish. “But what’s fascinating is that they cooperate more with clients when they are being observed by other potential clients,” said Dr Warburton. “This improves their “image” and their chances of attracting clients. Some cleaners cooperate with small clients to raise their image so as to deceive larger clients, which they then cheat on by biting them rather than removing their parasites!” Pretty industrious.

So next time someone tells you you have the memory of a goldfish? You be sure to remember to tell them about this research.

Adapted from an article from Animal Planet


Are Human-Animal Hybrids Coming?

Published August 2, 2011 in Love For Earthlings |
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The Academy of Medical Sciences in Britain has released a report exploring the possibility of mixing human cells of genes into animals for research purposes. They say the value to research into human disease warrants discussion and further scrutiny.

In the report they say, “This report considers research that involves the introduction of human DNA sequence into animals, or the mixing of human and animal cells or tissues, to create entities we refer to as animals containing human material (ACHM).”

Specific examples they give are dramatic changes to an animal brain using human cells to evaluate what consciousness or sentience is, cross-fertilization between human and animal reproductive material such as sperm and eggs to see what develops, genetic modifications to animals to make them resemble humans more or increase their capacity for speech.

In their own words, “Breeding of animals that have, or may develop, human derived germ cells in their gonads, where this could lead to the production of human embryos or true hybrid embryos within an animal.” (Source: Academy of Medical Societies)

Splicing human genes into rats for research purposes has been done for some years. Still, some of the scenarios described above seem like science-fiction novels or movies. The film Blade Runner foresaw a future filled with biologically designed organisms, both animal and human. Maybe it is not that far away.

As one commenter put it, “Give it a decade or two, and humanity is going to genetically engineer some very human-like animals.” (Source: Singularityhub.com)

Note: the pigs pictured above contain no human genes, but were genetically modified to produce less environmentally-damaging waste. Image Credit: Cecil W. Forsberg

Adapted from an article by Jake R.